Aspects described herein relate to a fixture for holding and displaying a visual target, and more specifically, to displaying a reflection of the visual target using a mirror to increase a viewing distance from a viewing location.
Night vision imaging systems, such as night vision goggles, are sometimes used by vehicle operators, such as pilots, to see the environment in dark conditions. Typically, night vision imaging systems use image intensifier tubes to amplify starlight and/or moonlight to generate images of an outdoor environment and display the generated images on a view screen. The flight deck of an aircraft typically includes illumination so that pilots can read the instruments, read checklists or maps, or perform additional tasks. For example, the flight deck may include various instruments with backlighting and/or floodlights to illuminate the flight deck. When used in the aircraft cockpit, the primary function of night vision goggles (NVGs) is to provide intensified imagery of distant objects in the outside environment. NVGs are very sensitive to light, and it is undesirable for NVGs to sense and intensify light from any sources other than those in the outside environment. Cockpit instruments and displays must remain readable at night by the unaided eye, but any cockpit lighting that is sensed and intensified by the NVG may cause circuitry in the NVGs to automatically decrease an intensifier gain, thereby degrading the NVG-aided visual acuity of the outside environment.
To ensure that a night vision imaging system is not amplifying flight deck illumination excessively, the effect of cockpit lighting on a night vision imaging system is typically tested in a flight simulator environment. During this test, a pilot or other person using the night vision imaging system (e.g., wearing night vision goggles) sits in a pilot's seat in a flight deck cockpit or simulator with cockpit instruments set to a night lighting mode. In the night mode, the outside environment is dark (e.g., a display screen is displaying a night scene or the display screen is blank) and the flight deck illumination is turned on. During the test, the pilot wearing the NVGs attempts to read a visual target, such as the United States Air Force 1951 Medium Contrast Resolution Resolving Power Target, which is illuminated using a starlight generator that simulates starlight illumination and radiance. The pilot or other operator identifies the target element that can just be discerned with no flight deck illumination. The flight deck illumination is then turned on to determine the effect, if any, the illumination has on the ability of the pilot or other operator to discern the target elements. Any changes in the ability to see the target can result in the need to make changes to the flight deck lighting design.